This investigation was carried out to try the application of pilocarpine hydrochloride (PC) solid dispersion as sustained release dosage form. Four preparations of PC with ethylcellulose and/or hydroxypropylmethylcellulose phthalate were prepared by the organic solvent method. The preparation D including PC : ethylcellulose : hydroxypropylmethylcellulose phthalate (1 : 9 : 10 at weight ratio) showed the best sustained release behavior in dissolution test among four preparations. The preparation D was examined by powder X-ray diffractometry and differential scanning calorimetry, and confirmed to be solid dispersion. Saliva secretory effect of preparation D was examined in healthy male volunteers, and its effect for Xerostomia was showed.
